Ventilating system



Sept. 8, 1953 J. A. MARQUARDTY VENTILATING SYSTEM 2 Sheets-Sheet 2 INVENTOR. (zigzag/6%,

I Jaizrz (ZN Filed Aug. 17, 1948 Patented Sept. 8, 1953' 2,651,250 VENTILATINGSYSTEM v John A. Marquardt, Elmhursh ljl, assignor,-by I mesne assignments, to Burgess-.

anning CompanyjLiber'tyville, Ill.,"a corporation of? Illinois Application August 17, 1948, Sl'-ia1 Ni). -44,"7 42 19 Claims. (01. 98-40,)

Thepresent invention: pertains to an improved ventilating system for the circulation of 'warm or-:cool air'inuan enclosed space, being particularly adaptedand devised'ior installation in railway passenger :cars, lbusses and like vehicles. However; theglprinciples ofthe invention are quite widely'applicable and are not limited in utili-ty to .-,passenger vehicle installations.

Two v,igeneral methods are employed in distributinge-air iniairw-rconditioning .--and* ventilating systems, namely,: the velocity distribution system and the pressure distribution system. In the former, :air is usually blown from grilles at sulfici'ent velocity to traverse and distribute itself throughout the: space to be conditioned, 'baflles and vanes being sometimes employed to control thesdirectioniof the air :stream. Considerable carez'must "berexerci'sedin the choice or design oflgriilesan'ri entering air velocity to'insure that thezair'will'travel the entire length of the space which: is serviced before returning, and under any circumstance itis difiicult to obtain uniform, draft free air distribution with the conventional velocitysystem. iThepresent invention involves -a modified "and improved distribution method. Under ithisl-princi-p'le the air is vcaused to -fiow through thezparalleliducts'of a two-dust system and is :carefully controlled and allowed to escapeiatmlow-velocity to the space serviced by the unitpthroughaopenings in said duct'system.

:Application of the .usual grille type velocity system to varailway car "ventilating installation would normally present some difiiculty, if :only because-10f the relatively-great length of the'vehi'cia -hencedt is 'ageneralobject of a the invention to surmount this difliculty I and 1 to insure a uniform, draft-free distribution .of -air,

heated-or .cool, 1 throughout an elongated interior atsaxum'fonntemperature, rangin'g'not more than a.few= degreesxthrough'out the :ent'ire v space which is 'zservedi sit isran'other general object of the inventionto provide aisimple, relativelyinexpensive ventilatingssystem or :unit which eliminates "the -use'- of conventional ducts, grille and other special openwhich is readily installed in existing passenger'vehicles T01 other locations, preferably-adiacent therlceiling" thereof, and which be'st adapts the distribution method to .theeflicientdistributionofventilatingair.in'a vehicle or. like interior.

..-2A:2still furtheregeneral object of the invention is itoprovide -a ventilating system 'or :unit of the foregoing character which operates on the:.prin- .cipleof therdistribution: of: air at very low velocity along andlthroughvagperforatedeeiling area, may

present inga multiplicity of widely distributed perforationstherein, with complete treedomfrom -drafts arising from localized, high velocity issuance of air through -said ceiling area, said-system emplaying apair on adjacent, separate though-communicating, parallel ducts extending along the ceiling and-means vto-supply air .under pressure to both of said ducts tor-longitudinal flow therethrough.

Yet :another and more specific object of the invention is to provide a'dual flow, double-duct ventilating system of the foregoing type composed ofv'ar-ious special perforated duct and baffle elements which are predeterminedlyassociated withone another and proportioned as to the size and amount of open areathereof so as to .efiect: a. controlled and uniform issuance and distributionchair-throughout all parts of the space which I J's-serviced.

A still-.rfurther object is to provide a system of the type referred I to-above, in which. provisions are:made to-cause a multiplicity of low velocity, laterally directed-air jets to issue from the interior-ota special, elongated, perforated and internal ductinto an elongated, external, perforated d-uct,= and :toemploy said jets or air streams somewhat in the manner of mechanical bafiles tointerrupt and .defiect air traveling lengthwise ofsaiddast namedduct on-the external side of said internal duct, thereby to insure uniform, equal volume and low velocity issuance of ventilating air from said system throughoutthe entire .le lgthof the=space .serviced'by the system.

:Theioregoing statements are indicative in a general wayof the natureof the invention, but other-andmore specific objects will be apparent to those skilled in the art upon a full understanding of the construction and operation of the system.

ingleuembodiment of the invention whereby th l oveobje'c'ts areattainedds i-llustr atedin the drawings, in which:

EFig. {1 is a fragmentary perspective view, parallybrcken away and in transverse vertical section to illustrate -structural details and the relationshiplofthe"component parts of the system asoperativeiy' installed in a structureito be ventilatedgfo'r' example, a railway car;

"Figs; "and 3 are, respectively, somewhat enlarged iragmentary views in vertical transverse sectionalcng lines corresponding approximately to 11mm: and-8-3 of Fig. 1, Fig. 3 being parti'all-y broken: away to show further structural details;

Fig. 4 is a bottom plan view of the system in accordance with the invention;

Fig. is a fragmentary view in vertical longitudinal section along a line corresponding approximately to line 55 of Fig. 4, and

Fig. 6 is a schematic view illustrating one of the basic principles involved in the operation of the present system.

Referring to the drawings, the reference numeral ID in Fig. 1 generally designates a railway car to which the system of the present invention is illustratively applied, although it is to be understood that said system is also susceptible of being installed in various other units, vehicular or otherwise. The system 01' unit as a whole is disposed lengthwise of the car and centrally of its width, being practically co-extensive in length therewith. The usual ceiling or upper deck of the car is designated ll, being spaced somewhat beneath the car roof I2; as illustrated in Figs. 1, 2 and 3. The duct-like ventilating unit of this invention is generally-designated as a whole by the reference numeral l3;it is arranged so that its lower surface lies'flush with the ceiling H (see Figs. 2 and 3). It is preferably closed at its rear end and at its forward end it is in receiving relation to a blower or like air supply source, as will be described.

The unit (3 is constituted by four main com ponents. One of these is the three sided, elongated main duct H which is constituted by parallel, imperforate side walls l5 abutting the roof l2 at the top thereof and a bottom perforated panel 16 extending beneath said walls, the aforefourth wall of duct l4.

said roof serving as 3. Another general component of the unit in the present instance is the special, rearwardly tapering trough or V-duct I! disposed internally of These provisions may take the form of an offset bracket 22 welded or otherwise aifixed to a duct side wall IS, an elongated angle iron 23 secured to a section or sections of perforated panel l6 and a hinge 24 pivotally articulating said angle iron and panel with the bracket. The opposite side of the panel IG- may be provided with a compressible vibration pad 25 cemented on an elongated angle iron 26 carried by said panel, which pad is engaged against a further elongated angle iron 2'! on the side wall l5. A standard and coextensive with the duct-i4, opening upwardly thereof. forward, vertical perforated bafile 18 arranged transversely of the duct M at the forward or entry end thereof, as illustrated in Fig, 1. The

A third basic component is a fourth general constituent in the present instance is a secondary vertical, ranged baffle 19, which is-located afew feet downstream or rearwardly of the baffle I8. These four general components are secured to one another in the relationship to be described in any conventional manner to constitute the built up ventilating unit l3. Saidunit disposed in alignment with and rearwardly spaced from a conventional blower 20 mounted in a suitable housing adjacent-the forward end of the space to be ventilated. The output of said blower is directed to the forward, intake end'of both ducts of the unit.

As stated above-the side walls 15 of the main duct I4 are imperforate and serve to seal said duct from the remainder. of the space between roof [2 and ceiling H on either side thereof. The lower ceiling panel 16 of duct [4 is provided with a multiplicity of perforations l6 through which the ventilating air issues to the car interior which is serviced. This panel may comprise a plurality of sheet metal sections arranged in end to end order and a'ppropriatelysupported by means disposed internally of the duct M. It has not been deemed necessary to illustrate and describe a particular arrangement in detail, however, suitable provisions may be incorporated to enable the panel IE to be unfastened and lowered for access to the interior of duct M, in cleaning, etc., as illustrated in dotted lines in Fig. 3.

transversely ar- "distributing outlet of said duct,

type of quarter turn fastener 21 is availed of to secure the panel it to the duct along this side.

The fastener may be manipulated through a hole in panel 16 by means of a suitable wrench or other tool.

In accordance with the invention, the panel it of duct M, which panel constitutes the air is uniformly perforated, as indicated by the reference numeral l6 to a sufficient extent to account for about 10% of its total face area. a

The special V-duct I1 is vertically tapered along its rearwardly extending dimension to such an extent that its apex rises about {e of an inch per foot of length. The taper is generally indicated in Figs. 1 and? and is illustrated in exaggerated degree in Fig. 5. The downwardly convergent side wall sections 28 of the duct H are disposed at a uniform angle of approximately to one another and, since this angle is constant throughout the length of the V-duct, it is apparent that the margins of said sections taper toward one another in the rearward direction, as well as toward roof l2 (see Fig. 3). In certain installations it may be found desirable to dispense with the feature of tapering said duct.

V-duct H is provided with a multiplicity of small air emission openings 29, sufficient to account for roughly 1% of its entire surface area, although this percentage may vary somewhat.

These openings are equally spaced on both sides of the duct.

The forward baffle l8 preferably take the form of a perforated, grille-like sheet metal plate appropriately secured marginally to the side walls H: of duct [4. Said bafile is flush with the forward open end of V-duct ll. Its primary purpose is to meter the proper proportions of air into the unit internally of and externally of said V-duct. Bafile 18 has a central V-shaped notch 30 which corresponds with the external outline of the V-duct and nestingly receives the latter in the operative relationship of the parts, and bafile l9 has a similar notch 30'. The baffles and ducts may be secured together by any appropriate means.

The area of the central longitudinal, V-shaped opening defined by the V-duct 11, i. e., between duct sections 28 and roof 12, represents approximately 40% of the total cross sectional area across the duct M, the remaining 60% being represented by the overall cross sectional area of the baffle 18. This baffle is punched out to provide a multiplicity of rectangular aperture 32 defined by the intersecting strips 33, which apertures occupy about 60%-70% of the total area of the bafile when they are fully exposed to the air directed against the unit by blower 20. Accordingly, the total maximum area of opening through said baffle is about 42% of the total cross sectional area of duct I4. Hence when the openings 32 are fully exposed they pass approximately the same amount of air to the duct ll externally Of V-duct H, as enters the latter. For

ems-moo practical purposes 'thevolume reaybe-considered equal. W a

-Adjustabi-lity of operation' may *be obta-"ined rby partially 'covering'thesopeni-ngs' fl ofi-baflle IR. A

suitable means for--aooonn alis'hing this may take the "form-"of a-control plate 34 similar to' the "baflle w'l nchis *gui'ded for sidewise movement in "a suitable transverse: channel or ways 35 extending across' duct t4. 'I he-control" plate-34 "abuts baifia t8 and i 'ren dered adinstable laterally by the wing nuts 3 fi-andwashersl3l which. hold itto said ballle. U-pon-loosening-said nuts thelcontrol plate 34 may be shifted to: displaceitsxrectanglular-mpem'ngs relative-to the similar.apertures 32 nf said baille as indicated in solid iines.in.Fig..:2. when in maxnnumx-cuteoffposition the plate.;34 reduoeszthe eifective aairsfiow :area through baffle -tl to'-about- 30'% of its total area, .as comparedto the abovei-mentioned 60l%-'Z0% :when the; plate 'ad isiinoperative. Suizficient clearanceis provided betweencplate tllandthezsides aofthe duct: Hand Neldnctlto permit saidzlateralsadiustment.

l :i'Dhe:,.-secondaryzzorxrear :baflle t9, which. is the .fourthibasiczcomponenirofythe. ventilating unit, is zloeatedcafemfeetto. thes rear-ofzbafile 8 and, like ithelatter;is:perforatedaata3-81tozanzextent-suffi- :cientitozexposezapproximatelyz50% of its: area for air flow therethrough. It is similar in outline to vhaflieal Sui-and isrsimilarly secured. in upright posi- :tion:. internally cof sthe .zmai-n .duct 14, extending tnansverselyacross thealatter.

, zfIhe. foregoing structuralzand. flow capacity relationships :resultina balanced, uniform distrihution Qfz airzfrom duct I 4--.when.air is introduced to the unit :13 by blowerZO.

1 .No-attempthasbeen made to; reproduce exactly iniihedrawings.thessize. of. the holeor perforation in-anylof.the walls panels.or:baifies of the system. .."In operation, assuming that said :blower is supplying \ain/tothe unitatmoderatevelocity and in .the.:directi-on of the length of the installation, aboutr50% thereof .nnimpededly enters the V- ;duct i7 and the remainder-passes through the apertures 32 of the forward bafile t8. In traversing the -V.-duct at moderate velocity the air therein issues. downwardly and. laterally through the perforations 2-9- in the side panels 28. into the duct -I 4y inthe-form. of a multiplicity ofsmall a-ir streams of considerable velocity, directed-at right angles to the length of the duct. Theseair streams orjets travel with a certain momentum, hence they maybe considered essentially asfluid barriers or -.bafiles. The action ,is shown schematically in Fig. 6, in which said baffles are denoted .3. They continuously impinge thelarger stream of air fiowing long-itudinallyin duct I 4 :on the outside of V-duct l1,throughout the entire length .of its travel causing .a certain amount .ofturbnlence in that stream.

The rearward taper, of said -V-duct, and its-resultant eifect of settin up a back pressure, tends .tomaintain the aforesaid air baffle action uni- ;form at all-zones in duct. However, as stated above, the system is satisfactorily operative when -the .taper .is omitted. :In any-embodiment, the normal tendency ofthe air whichis supplied. ex- :ternally Of'Vwd'uCt. I to flow theentire-length of -the unit before issuing through the perforations =16 .ofthe lowermost, panel IG-is interrupted and .counteracted by the aforesaid air baflles andturbulence. The. result is that portions ofthe moving air. induct M. are. continually. deflected downwardly, throughout its entire length-and caused to .issuethrough perforated panel [Bat very low velocity. The adjustment afforded by liheoontrol plate' flaenablestthe systenr tozbeiregulatedseasily to-meetal-lconditions sot-operation.

- fllhe ssecondary; perforatedtbafile L-9;:is.;:provided for the purposer of mechanically *bafliingztheaair :fiow LtoL-the. ducIt'JM, .i.@:e.,..to moderaterthe velocity of flomadjacent thesimmediate entry'zonetofr-zthe unit andx'thereby cpreventaaspiration. @As .distinguishediirom this, the sessential lfunction :of'. the forwardrbafflesldzis anmeteringione, insuring-that an eadeq uate Jportion :(-rcrug:hly;hal-f) .of a the snppliedzlby the blower .20: enters the Veduct: l1.

1 Asswi'llrber-revidem fromthe foregoing description, the;:presen1;isystemdoperate non the general principlesof employing a multiplicity of fluid-air shames,:.set.up :by a stream of air flowing along-itudinallyof one d-u'ct, which :baflles coact withxa EiMrther-air strea-m.rinjanother duct-across-which they.fiowutoscausaair to be distributed .fromsthe yent'ilatin'giunit in .nniformlydistributed :volume arid-sat cons-tant'velocity. :These fluidrbaflles-rare. in-eifect, the equivalent of a great multiplicity. of very;caretuIJy- Iaced-and= apportioned mechanir zcalabaifies, such-:as would be .called for alsystem operating according to the conventional theoryeof airdistri-bution. The advantages of the,- present unit :over such a :complex mechanical .bafllingv-nnit from-the standpoints ofcost ofinstallatiom engineering experimentation, .etc., are clear. Other advantages factors ;of.-.dra-ft :free :operation, uniform temperature -:-ma-intenanee .and thee-like are-.a-lso obtained. 7 p

Those skilled in the art willa-perceivethepossi- .bilityand perhaps the; desirability. of variousealterations in .detailor arrangement omhe features .ofthe above described unit, without vdeparting from the principles ofv the..invention .asreferred .toabove. It .is therefore intended [that the-invention be. construed .-as broadly. as is consistent with. the .spiritof the: accompanying .cla-ims.

,Lelaim: Q

sly-A vventilating structurescomprising :a .pair vofelongatedair flow ducts, bothof which-are provided with, perforated lower-members, ,one ,of

transversely of and .in flow obstructing relation .to .the outermost duct, .the cross-sectional varea of said internal duct being relativelyunobstructivelya exposed to longitudinal how of :air .thereinto inthe zone thereof adiacentzsaid-baifle.

-CI'QSSnSQCfiOIlEtL area of saidinternal ductbei-ng relatively..unobstructedly exposed to longitudinal'fiowof .air thereinto in. the zonethereoflad- ,jacent .said baffle.

/ (3. A -.-venti-lating..structuremomprising Qapair .of elongated air fiow..ducts,-both.of whichare provided .with perforated lower members. .one of .said ducts .being housed within 1 the 1 other a vertically. spaced relationship of said respec- .-and inwardly convergent portions, and aperiorated baflie disposed transversely of and inaflow obstructing relation to the outermost duct, the cross-sectional area of said internal duct being relatively unobstructedly exposed to longitudinal flow of air thereinto the zone thereof adjacent said baffle and approximating in size the total area of the perforations of said baille.

L -A ventilating structure comprising a pair of elongated air flow ducts, both of whichare provided with perforated air emission members, one of said ducts being housed within the other in a vertically spaced relationship of said respective air emission members, the perforations of the air emission member of the internal duct opening downwardly and sidewise to the interior of the outermost duct, and a perforated baflle disposed transversely and in flow obstructing relation to the outermost duct, the cross-sectional area of said internal duct being relatively unobstructedly exposed to longitudinal flow of air thereinto in the zone thereof adjacent said baffle. 5. A ventilating structure comprisin a pair of -'elongated ducts both of which are provided :with perforated lower members, one of said ducts being housed within the other in a vertically spaced relationship of said respective lower members, the lower surface of the internal duct being constituted by downwardly and inwardly convergent portions disposed in a V-shaped relation, a perforated baflie disposed transversely of and in 'flow obstructing relation to the outermost duct, said internal duct being unobstructedly exposed to longitudinal flow of air thereinto in the zone thereof adjacent said baffle, and a further perforated baflle disposed in similar, transverse relation to said outermost duct and spaced long-itudinally from said first named baflie.

6. A ventilating structure comprising a pair 'of-elongated ducts both of which are provided with perforated lower members, one of said ducts being housed within the other in a vertically spaced relationship of saidrespective lower members; the lower member of the internal duct being constituted bydownwardly and inwardly convergent portions disposed in a V-shaped relation, a perforated baflledisposed transversely of and in flow obstructing relation to the outermost duct, saidinternal duct being unobstructedly exposed to longitudinal flow of air thereinto in the zone thereof adjacent said baffle and being of a cross 's'ect'ionalarea approximating the total area of the perforations of said baffle, and a further perforated baflledisposed in similar, transverse relation to said outermost duct and spaced longituidinally fromsaid first named baille.

TEA ventilating structure comprising a pair offelongated ducts both of which are provided -with'perforated lower members, one of said ducts "being housed within the other in a vertically [spaced relationship of said respective lower members, the lower member of the internal duct being constituted by downwardly and inwardly convergeintfportions disposed in a V-shaped relation, a perforated baffle disposed transversely of and in flow obstructing relation to the outermost duct, "saidinternal duct being unobstructedly exposed to longitudinal flow of air thereinto in the zone thereof adjacent said baflie and being of a cross sectional area approximating the total area of the perforations of said bafiie, and a further rperforated baiile disposed in similar, transverse relation to said outermost duct and spaced rearwardly'from said first named baflle, said internal duct tapering longitudinally and converging along its length to asubstantially reduced cross sectional area.

8. A. ventilating; Structure comprising a pair of elongated, enclosed parallel ducts, both having perforated lower members, one of said ducts being housed within the other and the perforations of the lower member of the internal duct being disposed to open laterally and downwardly for the discharge of air therefrom at an oblique downward angleacross the outermost duct, a perforated baiile disposed transversely of and in flow obstructing relation to the outermost duct,said internal duct being relatively unobstruotedly exposed to longitudinal flow of ,air thereinto in the zone thereof adjacent said baflle. v

9. A ventilating structure comprising a pair of elongated, enclosed parallel ducts, both having perforated lower members, one of said ducts being housed within the other in a vertically spaced relationship of said respective lower members, the perforations of the lower member of the internal duct being disposed to open laterally and downwardly for the discharge of air therefrom at an oblique downward angle across the outermost duct, a perforated baffle disposed transversely of and in flow obstructing relation to the outermost duct, said internal duct being relatively unobstructedly exposed to longitudinal flow of air thereinto in the zone thereof adjacent said baflle.

10. A ventilating structure comprising a. pair of elongated, enclosed parallel ducts both having perforated lower members, one of said ducts being housed within the other in a vertically spaced relationship of said respective lower members, the perforations of the lower member of the internal duct being disposed to open laterally and downwardly for the discharge of air therefrom at an oblique downward angle across the outermost duct, a perforated baille disposed transversely of and in flow obstructing relation to the outermost duct, said internal duct being relatively unobstructedly exposed to longitudinal flow of air thereinto in the zone thereof adjacent said baflie and, means to adjust the effective area of opening through said baffle.

11. A ventilating structure comprising a pair of elongated, enclosed parallel ducts, both having perforated lower members, one of said ducts being housed within the other in a vertically spaced relationship of said respective lower members, the perforations of the lower member of the internal duct being disposed to open laterally and downwardly for the discharge of air therefrom at an oblique downward angle across the outermost duct, a perforated forward baffle disposed transversely of and in flow obstructing relation to the outermost duct, said internal duct being relatively unobstruotedly exposed to longitudinal flow of air thereinto in the zone thereof adjacent said baiile, means to adjust the effective area of opening through said baflie, and a further perforated bafile in similar, transversely disposed relation to said outermost duct, said further baffle being spaced longitudinally from said first named baflie.

12. A ventilating system comprising an elongated open-ended, laterally enclosed duct of substantial cross sectional area at the open end thereof, said duct having a generally horizontal discharge panel which is provided with a multiplicity of small downwardly opening discharge apertures, a second elongated, open-ended duct of generally V-shaped cross section disposed longitudinallyin said first duct, the convergent side panels of said V-duct being provided with perforations opening to said first duct,

mperforatedforward' transverse; bailie disposed across said firstw-ductadjgacent saidcopenrend thereof,- the crosa sectional. area. of. said. V-duct being unobstructedly; exposedto longitudinal fiowaof ;air=;therein-to in thezone-thereof adjacent said; baflle;.-, and: a. secondary perforated. baffledisposed transversely? of saidsfirst duct and externally-1 of :said. V -duct in longitudinally spaced relation to said; forward :baflle, said. \L-d-uct being adapted toreceiverair atttheopenend.thereoffor lateral: and downward. issue iin jet-form through the perforations e. of. said V-duct panels, thereby torbafliea the: flow ofiain along. saidfirst duct externally of said V-duct.-.

3. A ventilating system comprising an elongated; openeended laterally enclosed duct of substantial cross sectional area at the open end thereof, said. duct .having a; generally. horizontal discharge panel which is provided with a multiplicity of' small downwardly opening'discharge apertures, an elongated, open-ended duct of genorally V-shapedcross, section: disposed? longitudinally-in; said. first duct in verticallyspaced relation: abovesaid..dis.charge. panel, the 1 convergent. side panels of. Tsaid V-duct being providedwithsperforations. opening to :said first duct and beingrtaperedtoward one another and longitudil'lall yv along, their length: whereby,- to, con-- vergev to a:-;substantially reduced cross-sectional area, a'perforatedforwardtransverse baffle =disposed, across said first ductadjacent saidopen end: thereof, the cross seetional area: ofsaid azluctiloeing unobstructedly: exposed to l'ongitudinaliflow; of van .thGIQilltO-wilfbth'fi zone .thereof adjacent :said bafile. and approximating in size that portion; of. the. overall areaziof said bafile which is represented by the perforations therein, and a secondary perforated bafile disposed transversely of said first duct and externally of said V-duct in longitudinally spaced relation to said forward baflle, said V-duct being adapted to receive air at the open end thereof for lateral and downward issue in jet form through the perforations of said V-duct panels, thereby to bafile the fiow of air along said first duct externally of said V-duct.

14. A ventilating system comprising an elongated, open-ended, laterally enclosed duct of substantial cross sectional area at the open end thereof, said duct having a generally horizontal discharge panel which is provided with a multiplcity of small downwardly opening discharge apertures, an elongated, open-ended duct of generally V-shaped cross section disposed longitudinally in said first duct, the convergent side panels of said V-duct being provided with perforations opening to said first duct, a perforated forward transverse baflle disposed across said first duct adjacent said open end thereof, the cross sectional area of said V-duct being unobstructedly exposed to longitudinal flow of air thereinto in the zone thereof adjacent said baiile, a secondary perforated bafile disposed transversely of said first duct and externally of said V-duct in longitudinally spaced relation to said forward baiile, said V-duct being adapted to receive air at the open end thereof for lateral and downward issue in jet form through the perforations of said V-duct panels, thereby to bafile the flow of air along said first duct externally of said V-duct, and means to regulate the total effective area of air flow opening through the first mentioned baflle.

15. A ventilating system comprising an elongated, open-ended, laterally enclosed duct of substantiali. crosss sectional area; atthe open end. thereof, said duct havinga-generally horizontal discharge panel .whichis provided: with a multiplicity of small downwardly openingdischarge apertures, an. elongated; open-ended duct of generally- V-shaped-. crosssectiondisposed" longi tud-inally irr saidrfirst duct, the convergent sidepanels-of said .-V-duot beingprovided. with per-' forations opening .to said first duct, aperforated\ forward transversebafile-disposed aerossrsaid first duct adjacentzsaidvopen end thereof, the cross sectional area 7 of said. -V'-duct being un'obstructa edlyzexposedto longitudinal fiow" of air thereinto i.nthe zon-ev thereofadjacentr'saidbafile, a secondary perforatedbaflle '"disposed transversely of said first :duct and externally of said V-'duct:in longitudinally spaced-relation to. said forward baffle; said: V-d-uctbeing adaptedto receive-i air attthe openend thereof for lateral. and down,- ward issue. in jet. form through. the perforations of-said. V-ducttpanels; thereby: to: baflle thecfiow of" air along said first duct external-1y of said V-duct, and means to regulate the total effective area of 7 air flow" opening through said forward baflle;

16. 1Q: ventilatingjsystem comprising: an elongated, open-ended, laterally; enclosed first duct of substantial.crossrseetionalarea at theopen. endthereof, said d-uct having; agenerally horizontaldischarge-panel which istprov-ided with a- III-H1. tiplicity -of small downwardly' opening;discharge apertures, anelongated,- open-ended ductof generally V-shapedcross section disposed longittudinally said. first duct: invertically spacedrree la-tion above said discharge panel, thaconvergen-t side panels=- of said r V' duct r being 1 provided" with perforations opening to said first duct and being tapered toward one another longitudinally along their length whereby to converge to a substantially reduced cross-sectional area, a perforated forward transverse baflle disposed across said first duct adjacent said open end thereof, the cross sectional area of said V-duct being unobstructedly exposed to longitudinal flow of air thereinto in the zone thereof adjacent said baifie and approximating in size that portion of the area of said bafile which is represented by the perforations therein, a secondary perforated baflle disposed transversely of said first duct and externally of said V-duct in longitudinally spaced relation to said forward baffle, said forward bafile and V-duct being adapted to receive air at the open end thereof for lateral and downward issue in jet form through the perforations of said V- duct panels, thereby to baflie the flow of air along said first duct externally of said V-duct, and means to regulate the total effective area of air flow opening through the first mentioned bafile.

17. A ventilating structure comprising a pair of adjacent, parallel, elongated ducts which are substantially coextensive in length and are separated from one another by an air-pervious wall portion common to both thereof, said ducts having adjacent forward ends open and exposed at a common intake plane for the reception of parallel streams of air flowing rearwardly along the length of both thereof, said air-pervious wall portion causing transverse jets to issue from one of said ducts into the other at an angle to the direction of air flow in the latter, said other duct having an air-pervious wall portion exposed to an external space to be ventilated, said last mentioned air pervious wall portion having a multiplicity of widely distributed perforations therein,

.said ducts into the other at an angle to the direction of air flow in the latter, said other duct having an air-pervious Wall portion exposed to an external space to be ventilated, said first mentioned air pervious wall portion having a multiplicity of widely distributed perforations therein, and plural bafiie means disposed in and spaced along the length of said other duct to control the air flow therein, one of said baffle means being arranged substantially at said common intake plane.

19. A ventilating structure for a space to be ventilated having a ceiling, comprising a pair of adjacent, parallel, elongated ducts which are substantially coextensive in length and are separated from one another by an air-pervious wall portion common to both thereof, said ducts having adjacent forward ends open and exposed at a common intake plane for the reception of parallel streams of air flowing rearwardly along the length of both thereof, unitary means associated with the forward ends of said, ducts to cause streams of air to enter and traverse both thereof, said air-pervious wall portion causing transverse jets to issue from one of said ducts into the other at an angle to the direction of air flow in the latter, said other duct having an air-pervious wall portion exposed to an external space to be ventilated, said air-pervious wall portions each having a multiplicity of widely distributed perforations therein, the perforated area of the first mentioned wall portion being less than the perforated area of the second mentioned wall portion and said air-pervious wall portion exposed to the external space being substantially flush with and forming a part of the ceiling, and means for proportioning the amounts of said air entering said ducts respectively.

JOHN A. MARQUARDT.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,660,758 Miller Feb. 28, 1928 1,863,949 Stewart June 21, 1932 1,999,148 Anderson Apr. 23, 1935 2,033,069 Hagen et a1 Mar. 3, 1936 2,093,306 Carson Sept. 14, 1937 2,155,632 Anderson Apr. 25, 1939 r 2,199,341 Henney Apr. 30, 1940 2,204,114 Anderson June 11, 1940 2,218,190 Anderson Oct. 15, 1940 2,251,682 Leadbetter Aug. 5, 1941 2,304,628 Damerel Dec. 8, 1942 2,340,252 Palmer Jan. 25, 1944 2,422,560 Palmer June 17, 194'! 2,422,782 Hemming June 24, 1947 2,424,828 Keep July 29, 1947 

